No prior art patent search was conducted on the subject matter of this specification in the U.S. Patent Office or any other search facility.
I am aware of my own U.S. Pat. No. 4,137,447, as being probably the most relevant prior art. My prior patent teaches an electric heater plate in which there is a substantial reduction in the amount of silver ceramic material used to form the heater plate.
My prior patent teaches an electric heater plate which is formed on one surface of a sheet of tempered glass. The one surface of tempered glass has a plurality of thin lines of a silver ceramic material bonded thereto, the thin lines extending in a generally parallel but spaced apart relationship across the sheet of glass. Left hand and right hand end portions of the plurality of thin lines are interconnected by a thin interconnection area of a silver ceramic material. A small terminal area of silver ceramic material is also associated with each of the interconnection areas located at opposite ends of the plurality of thin lines. A termination area is also bonded to the one surface of the sheet of tempered glass at a position spaced from the left hand and right hand interconnection areas. A thin copper strip is bonded to each of the terminal areas and the termination area associated with the left hand or right hand interconnection area to electrically interconnect the same. Electrical leads are connected to each of the pair of termination areas to provide a connection to a power system. When the power system is actuated, current flows through the plurality of thin lines in order to heat the tempered glass sheet. If the tempered glass sheet in installed as a rear window of a motor vehicle, the heat generated by flowing the current through the thin lines can defog and deice the window.
The structure proposed in this specification is one which once again substantially reduces the amount of silver ceramic material used in an electric heater plate construction. The structure proposed in this specification is also one which retains terminal areas formed of silver ceramic material so that secure bonds of electrical leads may be made thereto. The reduction in the amount of silver ceramic material used in forming the heater plate results in a significant cost savings.
The heater plates formed in accordance with the teachings of this specification have particular utility if they are formed on a sheet of glass which acts as the rear window of a motor vehicle. Electrical energy may be flowed through the heater plate construction in order to heat the same to cause a deicing and defogging action on any moisture which may have condensed upon or frozen upon the rear window.